Sales sub ledger do not reconcile to Balance Sheet

Ok I am working with Great Plains for 14 years and I can not believe that I can not reconcile Account Receivable Sub ledger to Balance Sheet.

We are using two different sub ledger -one for external costumers one for internal.  I just have checked all possible scenario,  mix match posting date and document date.  

Please any advise where to go and look for my error.


Thank you